共查询到17条相似文献,搜索用时 156 毫秒
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对基于半导体光放大器(SOA)交叉增益调制(XGM)效应的全光波分复用一光时分复用(WDM—OTDM)转换后的两路时分复用输出信号的消光比(ER)特性进行了分析。研究了两路波分复用的输入抽运光和探测光的功率、波长、抽运光的消光比、数据速率以及半导体光放大器的偏置电流、腔长和模场限制因子对转换信号消光比的影响。模拟结果表明,增大抽运光输入功率,选择长波长抽运光,可以增加转换光相应信道消光比,但减小了相邻信道的输出消光比;增加抽运光消光比,可以提高转换光消光比,但各个信道增长幅度不同;减小探测光输入功率,选取短波长探测光波长,增加半导体光放大器的腔长和模场限制因子以及大的偏置电流可提高转换光消光比;对于两路或多路波分复用信号转换时分复用信号的过程中,一定要考虑转换光每个信道消光比的均衡。 相似文献
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信号光的啁啾特性在很大程度上会影响量子点半导体光放大器(QD-SOA)的性能,引起传输信号的走离效应,使误比特率增高。为了改善这一特性,对QD-SOA全光波长转换器的啁啾特性进行了系统分析,基于QD-SOA的交叉增益调制效应的全光波长转换原理,采用牛顿法和4阶龙格-库塔法求解速率方程和光场传输方程,计算了注入电流、抽运光脉宽和抽运光消光比变化时QD-SOA全光波长转换器输出变换光的啁啾值。结果表明,增大抽运光脉宽、减小注入电流和抽运光消光比均可减小变换光的啁啾值,通过优化这些参量可以减小啁啾的影响,但在设计QD-SOA全光波长转换器时,要考虑抽运光消光比和变换光啁啾之间的均衡。 相似文献
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在半导体激光器实现波长转换的理论模型中引入互耦合系数, 根据改进后的波长转换模型, 得出了波长转换的误码率特性与理论模型中的互耦合系数的关系, 并进行了数值模拟和实验验证。数值模拟结果表明, 互耦合系数的大小取决于信号光和探测光功率及其波长间隔, 互耦合系数越大, 波长变换的误码率越小。理论与实验结果表明, 只有在大的信号光功率、小的探测光功率和较小波长间隔情况下, 即当互耦合系数取值较大时, 波长转换的误码率才能达到最小, 信号光功率的减小及探测光功率的偏大均会增大系统的误码率。 相似文献
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增益调制型波长转换中信号光波长的选择 总被引:2,自引:2,他引:0
增益调制型波长转换中 ,为得到转换后信号最大的消光比 (ER) ,信号光波长应该比半导体光放大器 (SOA)的小信号增益峰值波长长。采用分段模型 ,考虑了SOA中增益谱的不对称性以及增益峰值波长随载流子密度的漂移 ,深入研究了信号光功率 ,ER ,参考光功率 ,波长以及SOA注入电流对选择信号光波长λpk ,s 以及消光比改善量的影响。模拟计算表明 ,信号光功率每增加 3dB ,λpk ,s 就需向长波长移动约 7nm。信号光ER增加、参考光功率增加以及SOA注入电流的增加 ,λpk ,s 需向短波长移动。消光比改善量随信号光功率和电流的增加而显著增加 ,随信号ER的增加而降低 ,但是参考光功率和波长变化时影响不大 相似文献
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An analytical theory describing all-optical wavelength converters based on cross-gain modulation (XGM) in semiconductor-optical amplifiers is derived. Our theory consists of two parts: a large-signal analysis yielding the transmission function for the signal, and a small-signal analysis in order to describe the transformation of the signal and probe intensity noise. Both the large-signal as well as the small-signal theory reveal similar performance for the co- and the counterpropagating injection scheme for bit rates up to 2.5 Gb/s. This is confirmed by computer simulations. Consequently, the counterpropagating configuration is preferable because the implementation is simpler and conversion to the same wavelength is possible. In order to increase the conversion efficiency it is better to reduce the average signal power than to increase the probe power, which additionally reduces the output power range. However, there is a tradeoff between conversion efficiency and output extinction ratio. According to the small-signal analysis, the relative-intensity noise (RIN) due to the probe and due to the amplified spontaneous emission is negligible. Moreover, the converted signal has a lower RIN than the input signal 相似文献
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Signal-induced birefringence and dichroism in a tensile-strained bulk semiconductor optical amplifier (SOA) are demonstrated in a counterpropagation scheme. The polarization azimuth rotation and the change of ellipticity angle of the probe light are presented on the Poincare/spl acute/ sphere and can be calculated by the Stokes parameters. All-optical wavelength conversion (inverted/noninverted and upconversion/downconversion) based on cross polarization modulation (XPolM) in SOAs are investigated. It is shown that a bit error rate (BER) of <10/sup -9/ can be achieved and an extinction ratio of > 9 dB can be obtained at a bit rate of 2.488 Gb/s with a 2/sup 31/-1 non-return-to-zero (NRZ) pseudorandom bit sequence (PRBS). Because of the larger birefringence effect induced by the pump light in the longer wavelength range, upconversion shows better performance than downconversion. Compared with the noninverted case, inverted wavelength conversion shows better performance due to the positive contribution from cross gain modulation (XGM), which takes place simultaneously with XPolM. 相似文献
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Wiesenfeld J.M. Glance B. Perino J.S. Gnauck A.H. 《Photonics Technology Letters, IEEE》1993,5(11):1300-1303
Data at 10 Gb/s has been translated from an input signal wavelength to another wavelength, either longer or shorter, using gain compression in a 1.5-μm semiconductor optical amplifier for wavelength conversion. To achieve operation at such high bit rates, the probe (shifted) input must be intense enough to compress the gain of the amplifier significantly. This reduces the gain recovery time of the amplifier because of probe stimulated emission. A consequence of the intense probe is an extinction ratio deduction. Using moderate input powers, wavelength conversion is achieved over a 17-nm (2-THz) range, with 0.7-3-dB power penalties 相似文献
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A theoretical model is presented to analyze the noise transfer characteristics in a semiconductor optical amplifier (SOA) under the excitation of a noisy pump signal and a noise-free probe signal. An analytical expression is derived for the optical signal-to-noise ratio (OSNR) of the output probe signal from the SOA. The influence of the gain saturation of the SOA, and the pump and probe signal powers on the noise transfer characteristics is investigated. The noise transfer model is used to determine the output noise power of a delay interference wavelength converter. An analytical expression is obtained for the nonlinear phase change in the SOA, which determines the output power of the wavelength-converted signal. These results show that the noise transfer in the wavelength conversion can be suppressed by increasing the probe signal power, but that the improvement in the output signal OSNR relative to the input signal OSNR is accompanied by a reduction in the conversion efficiency. This fundamental tradeoff can be readily investigated during the design optimization process using the concise results derived in this paper. 相似文献